Field of the Invention
The present invention relates to an antenna, especially to a ten-frequency band antenna for enhancing the frequency response of the low-frequency segment and bandwidth of the high-frequency segment.
Description of Prior Art
The current commercially available planar inverted-F antenna (PIFA) is generally formed by printing metal material (such as copper) on printed circuit board (PCB) with two-dimensional printing technology. Alternatively, metal membrane is pressed into three-dimensional multi frequency band antenna.
The multi frequency bands signal transmission/reception can be achieved by changing the two-dimensional radiation patterns or the geometric shape of the three-dimensional radiation bodies. However, the antenna formed on PCB or formed by pressing metal membrane into radiation body need a specific volume to ensure signal transmission/reception quality and prevent signal tuning problem caused by environment. Moreover, the electronic device needs an internal space for arranging the PIFA structure, this causes impact on light weight and compact requirement of the electronic devices.
To overcome above problem, the radiation body of the antenna can be fabricated on a rectangular ceramic carrier. As shown in FIGS. 1 and 2, the carrier 101 of the antenna 10 has a high-frequency radiator 102 and a low-frequency radiator 103 on the surface thereof and the carrier 101 is fixed on the PCB 20. The PCB 20 has a ground metal plane 201, a signal feeding micro strip 202 and a ground wire 203 on two faces thereof, where the signal feeding micro strip 202 connects with the ground wire 203 and the radiator of the carrier 101. The high-frequency radiator 102 is arranged on the right side of the carrier 101 and the low-frequency radiator 103 is arranged on the left side of the carrier 101. The antenna 10 is electrically connected to the PCB 20 and the area of the ground metal plane 201 corresponding to the low-frequency radiator 103 is smaller than the area of the ground metal plane 201 corresponding to the high-frequency radiator 102. Therefore, the low-frequency radiator 103 suffers more to the ground shielding and the frequency response (see label A in FIG. 2) is not satisfactory. Moreover, the bandwidth of the high-frequency radiator 102 is not wide enough (only covering 6 bands as shown by label B in FIG. 2). As a result, the signal transmission/reception quality is poor and signal transmission/reception bandwidth is limited.